DESCRIPTION: Babies who are born prematurely and/or are underweight at birth are 20-80 times more likely to die before their first birthday. A significant proportion of preterm deliveries occur in women who are free of known risk factors. Periodontal disease is emerging as a potential risk factor although the results from human studies are equivocal. The long-term objective of this research is to further evaluate the extent to which the infections of periodontal origin play a role in preterm delivery. The primary Specific Aims of this project are 1) to measure the association between periodontal pathogens in cervical and vaginal samples of pregnant women and preterm birth, and 2) to measure the association between prenatal maternal serum IgG levels against specific periodontal pathogens and preterm birth. These Aims will be accomplished by conducting a nested case-control study within a large ongoing cohort study at the New York University Medical School (March-of-Dimes Study). Frozen serum and cervico-vaginal samples, data on biochemical markers such as IL-6, IL-8, TNFalpha, and Thrombin-antithrombin complexes, and validated questionnaire data on quality-of-life are available from this study. As of October 1,2003, there were 1579 subjects enrolled in this study and 1054 have already delivered (7% preterm deliveries and 10% low birth weight). Sixty-nine percent were Hispanic and 85% were 19-34 years of age. This study has two more years of enrollment remaining with an estimated 215 new recruits per year. Accordingly, we estimate that by October 2005 there will likely be 140 preterm and 1869 full term deliveries. Three pair-matched controls for each preterm delivery case will be selected from the full-term delivery subjects based on age, race, and date of delivery. Periodontal pathogens will be measured in cervico-vaginal samples using a checkerboard assay, and periodontal pathogen-specific IgG levels will be measured in serum samples using ELISA. Conditional logistic regression analysis will be used in the data analysis. As a secondary Aim, on an exploratory basis, levels of periodontal pathogens in oral, cervical, and vaginal samples, and periodontal pathogen specific serum IgG levels will be correlated with each other and also with preterm birth using fresh samples collected from the subjects that will be recruited to the March-of-Dimes Study after this application is funded (October 04-Oct 05; N=215). The proposed research is important because it will help identify the nature and the strength of the association between preterm delivery and periodontal disease-related factors which are modifiable in comparison to a majority of obstetrical risk factors that are not as easily changed. These associations have potential application in the early diagnosis and prevention of preterm deliveries. A major strength of the study is the efficacy gained by utilizing existing data and samples from a large cohort study. The collective expertise of the investigative team and the excellent clinical and research facilities are additional strengths.